The present invention broadly relates to a new and improved construction of a lapping machine for lapping gears or gear wheels, especially two curved-tooth bevel gears or the like.
Generally speaking, the lapping machine for lapping two curved-tooth bevel gears or gear wheels is of the type comprising a speed-regulated electric motor for driving one of the two bevel gears.
Such type of lapping machines used for lapping a bevel gear or hypoid pair are known, for example, from Swiss Pat. No. 530,845, which is cognate to U.S. Pat. No. 3,724,042, granted Apr. 3, 1973 and Swiss Pat. No. 580,461, which is cognate to U.S. Pat. No. 3,994,098, granted Nov. 30, 1976, contain a device for driving one bevel gear and for braking the other bevel gear, as well as a control device for setting the desired lapping pressure. During the lapping operation or process, the two rotating spindles or shafts, at each of which there is mounted a respective one of the two bevel gears, are so moved with respect to one another that in the case of crown or localized-bearing teeth, the lapping contact migrates over the tooth flanks. The lapping machines are equipped with additional means in order to produce and control additional or supplementary movements in the defined directions V, H and J. Apart from the aforementioned lapping movements, the lapping pressure is a very important parameter. The corresponding rolling pressure is produced by the brake drive in both rotation directions (the correspondingly effective push tooth flank and pull tooth flank). In the known lapping machines, the so-called rolling pressure has the same value on all tooth flanks (that is, for example, 0.05 Newton/mm.sup.2) This property is particularly disadvantageous if there is present an asymmetrical hardening distortion by virtue of the hardening of the individual gears. As the parameters H and V are defined by the gear tooth with the greatest hardening distortion, subsequently, all the tooth flanks are lapped in the same way.